Preheat Oven: Begin by setting your oven to 350°F (175°C) and lining two baking sheets with parchment paper.

Cream Butter and Sugars: Beat the softened unsalted butter with granulated sugar and brown sugar until light and fluffy.

Incorporate Eggs: Add the large eggs one at a time, mixing well after each addition.

Mix Dry Ingredients: Whisk together the all-purpose flour, baking soda, salt, and cocoa powder. Gradually mix into the wet mixture.

Add Peppermint: Gently fold in the crushed peppermint candies to evenly distribute them throughout the cookie dough.

Bake Cookies: Scoop tablespoon-sized balls of dough onto the prepared baking sheets, spacing them two inches apart. Bake for 10-12 minutes.

Cool: After baking, transfer cookies to cooling racks and allow them to cool completely.